Objective: to analyze the possibility of using xenopericardium for breast reconstruction in cancer Materials and methods: the article presents a clinical case of a patient diagnosed with breast cancer who underwent a subcutaneous mastectomy with simultaneous reconstruction with an endoprosthesis and a xenopericardium to strengthen the lower slope of the breast. Results: in our study, a good cosmetic result was obtained, and the presence of xenopericardium does not affect the conduct of postoperative courses of chemotherapy and radiation therapy. Conclusion: we present the first experience of using bovine pericardium in Russia for breast reconstruction in patients with breast cancer. Xenopericardium BioLAB-PP/PA of domestic origin was used to strengthen the lower slope of the reconstructed MJ using a silicone implant. © 2021 Izdatel'stvo Meditsina. All rights reserved.